Hair cell tip link breakage and regeneration is a model for the temporary threshold shift resulting from low-frequency noise-induced hearing loss. The research in this proposal will characterize the process of tip link regeneration at a molecular level. The aims of this proposal are to characterize the location of tip link proteins and myosin motors after tip link disruption, determine how inhibiting the interaction of tip link proteins affects regeneration of broken tip links, and to explore the array of hair bundle proteins that are dynamic during tip link regeneration. The research in this proposal will examine immunohistochemical localization of proteins in the hair bundle, analyze the presence of tip links by scanning electron microscopy, test the ability of truncated tip link proteins to inhibit regeneration in dominant negative experiments, and compare the protein content of hair bundles that are regenerating tip links to control hair bundles using mass spectrometry. By studying regeneration of broken tip links, the dynamics of the mechanotransduction complex in response to stress will be examined. RELEVANCE: Approximately 36 million American adults are affected by hearing loss. Cells in the ear that detect sound are susceptible to damage, and these cells can not be replaced by the body or by scientific methods at this point. The overall aim of this research is to understand how these cells replace damaged components necessary for their function, which is of utmost importance to all forms of hearing loss.